fix: support asymmetric matchers

package.json

@@ -62,7 +62,8 @@
   },
   "prettier": "@viamrobotics/prettier-config",
   "peerDependencies": {
-    "vitest": ">=0.31.0 <1.0.0"
+    "vitest": ">=0.31.0 <1.0.0",
+    "@vitest/expect": ">=0.31.0 <1.0.0"
   },
   "devDependencies": {
     "@typescript-eslint/eslint-plugin": "^5.59.5",
@@ -71,6 +72,7 @@
     "@viamrobotics/prettier-config": "^0.0.1",
     "@viamrobotics/typescript-config": "^0.0.3",
     "@vitest/coverage-istanbul": "^0.31.0",
+    "@vitest/expect": "^0.31.0",
     "concurrently": "^8.0.1",
     "eslint": "^8.40.0",
     "eslint-config-prettier": "^8.8.0",

src/behaviors.ts

@@ -1,3 +1,5 @@
+import { equals } from '@vitest/expect';
+
 export interface BehaviorEntry<TArgs extends unknown[], TReturn> {
   args: TArgs;
   returnValue?: TReturn;
@@ -52,7 +54,7 @@ const behaviorHasArgs = <TArgs extends unknown[], TReturn>(args: TArgs) => {
     let i = 0;
 
     while (i < args.length || i < behavior.args.length) {
-      if (args[i] !== behavior.args[i]) {
+      if (!equals(args[i], behavior.args[i])) {
         return false;
       }
 

test/vitest-when.test.ts

@@ -2,6 +2,21 @@ import { vi, describe, expect, it } from 'vitest';
 
 import * as subject from '../src/vitest-when.ts';
 
+declare module 'vitest' {
+  interface AsymmetricMatchersContaining {
+    toBeFoo(): unknown;
+  }
+}
+
+expect.extend({
+  toBeFoo(received) {
+    return {
+      pass: received === 'foo',
+      message: () => '',
+    };
+  },
+});
+
 const noop = () => null;
 
 describe('vitest-when', () => {
@@ -16,6 +31,10 @@ describe('vitest-when', () => {
 
     subject.when(spy).calledWith(1, 2, 3).thenReturn(4);
 
+    expect(spy()).toEqual(undefined);
+    expect(spy(1)).toEqual(undefined);
+    expect(spy(1, 2)).toEqual(undefined);
+    expect(spy(1, 2, 3, 4)).toEqual(undefined);
     expect(spy(4, 5, 6)).toEqual(undefined);
   });
 
@@ -205,4 +224,23 @@ describe('vitest-when', () => {
 
     expect(spy(1, 2, 3)).toEqual(1000);
   });
+
+  it('should respect asymmetric matchers', () => {
+    const spy = vi.fn();
+
+    subject
+      .when(spy)
+      .calledWith(expect.stringContaining('foo'))
+      .thenReturn(1000);
+
+    expect(spy('foobar')).toEqual(1000);
+  });
+
+  it('should respect custom asymmetric matchers', () => {
+    const spy = vi.fn();
+
+    subject.when(spy).calledWith(expect.toBeFoo()).thenReturn(1000);
+
+    expect(spy('foo')).toEqual(1000);
+  });
 });